Syntheses and crystal structures of three tri-phenyl-sulfonium halometallate salts of zinc, cadmium and mercury.

Bis(tri-phenyl-sulfonium) tetra-chlorido-zinc(II), (C(18)H(15)S)(2)[ZnCl(4)] (I), bis-(tri-phenyl-sulfonium) tetra-chlorido-cadmium(II), (C(18)H(15)S)(2)[CdCl(4)] (II), and bis-(tri-phenyl-sulfonium) tetra-chlorido-mercury(II) methanol monosolvate, (C(18)H(15)S)(2)[HgCl(4)]·CH(3)OH (III), each crystallize in the monoclinic space group P2(1)/n. In all three structures, there are two crystallographically independent tri-phenyl-sulfonium (TPS) cations per asymmetric unit, each adopting a distorted trigonal-pyramidal geometry about the S atom (S-C bond lengths in the 1.77-1.80†à range and C-S-C angles of 100-107°). The [MCl(4)](2-) anions (M = Zn(2+), Cd(2+), Hg(2+)) are tetra-hedral; their M-Cl bond lengths systematically increase from Zn(2+) to Hg(2+), consistent with the larger ionic radius of the heavier metal. Hirshfeld surface analyses show that H⋯H and H⋯C contacts dominate the TPS cation environments, whereas H⋯Cl and S⋯M inter-actions anchor each [MCl(4)](2-) anion to two surrounding TPS cations. Weak C-H⋯Cl hydrogen bonds, as well as inversion-centered π-π stacking, generate layers in (I) and (II) and dimeric [(TPS)(2)-HgCl(4)](2) assemblies in (III).